Achieving high capacity by vanadium substitution into Li2FeSiO4 for Li ion battery
- 材料学院－会议论文 
The feasibility of vanadium substitution into Li2FeSiO4 to achieve beyond one electron reaction to enhance capacity of cathode material for lithium ion battery is investigated by first-principles calculation based on density functional theory (DFT) within the generalized gradient approximation adding Hubbard-like correlation (GGA+U). The evolutions of the local structures and electronic structures for Li2Fe0.5V0.5SiO4 upon delithiation are analyzed in detail. It is demonstrated that vanadium substitution into Li2FeSiO4 may be thermodynamically possible to achieve more than one lithium ion extractions and, therefore, to significantly enhance the capacity of the Li2FeSiO4 cathode material, and improve electronic conductivity with lower band gap to Li2FeSiO4. Smaller cell parameter changes and more minor local structural distortions with vanadium substitution might be beneficial to stabilize the delithiated phases.